Noisecatcher
Field guide — ethos, vocabulary & practice
Part of the Politics of Noise research practice by Sylvain Souklaye
What this is
Noisecatcher is a free, open web application that gives anyone with a smartphone the ability to measure noise pollution in real time, understand its health consequences, and contribute to a living, peer-to-peer map of acoustic environments.
It is an electroacoustic instrument — a civic device that mediates between the acoustic world and collective knowledge. It is also a co-presence device: through its peer-to-peer community layer, listeners who are physically dispersed become acoustically present to one another, sharing evidence of the sonic conditions they inhabit without a central server, without surveillance infrastructure.
It is a civic instrument, an activist tool, and a phenomenological device. Its aim is to democratize acoustic monitoring — to give communities the means to document, contest, and act on noise as an environmental and social justice issue.
Ethos & practice
The instrument and its performer
Like any electroacoustic instrument, Noisecatcher requires a performer. The smartphone alone is inert — it becomes an instrument only through the engaged body of a listener. The microphone transduces pressure into voltage; the algorithm transduces voltage into meaning; but the listener provides the intentionality that makes the act of listening political. You are not a user of this tool. You are its performer, its operator, its witness.
The human device
The human body is the primary sensing device. The smartphone makes nothing perceptible that the ear has not already received. The human device is the necessary condition for the tech device to exist. You — your presence, your attention, your body in a place — are the instrument.
External microphones are welcome and improve measurement quality. Lavalier, cardioid, or omnidirectional mics connected via the headphone jack, USB-C, or Lightning are detected automatically. A device selector appears on the Meter screen when multiple inputs are available.
Noise-canceling earphones and earbuds are explicitly forbidden during a Noisecatcher session. This is not a technical constraint — it is an ethical one.
Active noise cancellation severs three fundamental connections:
- People from each other. A listener wearing noise-canceling headphones removes themselves from the acoustic commons. The shared sonic condition — the condition that generates solidarity — is dissolved.
- People from their environment. The soundscape carries information: about danger, inequality, the presence of others. Canceling it cancels the evidence. What is not heard cannot be documented or contested.
- The self from its own condition. The self is at the center of the listening experience. To cancel ambient sound is to make oneself less present. Deep listening begins with accepting what is there.
Noise cancellation is a profitable industry built on privatizing a response to a public health crisis. Binaural headsets without active cancellation are acceptable for listening to recordings.
Deep listening as political act
The practice of listening without cancellation — of attending fully to the acoustic environment — is both a phenomenological discipline and a political stance. It insists that the conditions of noise are real, shared, and worth documenting. It refuses private escape in favour of collective witnessing.
When you measure sound, you name a condition. When you pin a location, you make an argument about space, power, and the right to a liveable acoustic environment. Listening here is social. Listening here is political.
WHO reference thresholds
| Level | Range | Health context |
|---|---|---|
| Safe | 0–69 dB(A) | Below WHO environmental noise concern threshold |
| Caution | 70–84 dB(A) | Prolonged exposure may cause hearing fatigue; sleep disturbance risk |
| Dangerous | 85–99 dB(A) | Permanent hearing damage possible after 8 h/day; cardiovascular risk |
| Critical | 100+ dB(A) | Rapid hearing damage; acute pain possible above 120 dB; LRAD range |
Key vocabulary — from the Abécédaire
What to do with a measurement
- Document precisely. Note time, location, duration, and source category. A GPS-tagged pin with a decibel reading is civic evidence.
- File a formal complaint. Most jurisdictions have environmental noise complaint mechanisms — municipal noise offices, environmental agencies, planning authorities. Use the Act section of the app for country-specific resources.
- Coordinate with neighbours. Repeated measurements from multiple people at multiple times of day constitute a pattern. Patterns have legal weight.
- Submit to journalists and researchers. Tagged, timestamped data is usable evidence for investigative reporting, academic research, and legal advocacy.
- At a protest or near acoustic weapons. Protect your hearing first — distance yourself, use passive ear protection if available. Record second. Your data can support accountability investigations and press documentation.